# Synaptic and Circuit Interactions to Shape Multisensory Processing

> **NIH NIH R01** · NEW YORK UNIVERSITY SCHOOL OF MEDICINE · 2020 · $375,517

## Abstract

A critical step during sensory processing is the extraction of relevant information about the outside world from a
host of distracting sensory inputs. One mechanism for generating salience is to associate sensory information
from ongoing experiences with memories derived from past sensory experiences. Where and how these
functional associations occur in the brain are central questions in neuroscience. This proposal aims to fill this
gap by exploring circuit interactions and single neuron computations that help assign mnemonic
valence to sensory signals. In this study, we propose that the hippocampus—the center of learning and
memory—plays a crucial role in gating sensory information flow through its reciprocal circuit interactions with
the entorhinal cortex, a hub for processing multisensory information. To test this hypothesis, we will use
anatomical and functional connectivity mapping experiments to validate how hippocampus communicates with
entorhinal cortex output layers (Aim 1). We will assess how hippocampal inputs modulate the short-term
plasticity dynamics of excitatory-inhibitory synaptic transmission in the entorhinal cortex (Aim 2). Finally, we
will test whether the hippocampus actively modulates the synaptic strength and gain of sensory inputs to
entorhinal cortex through dendritic integration and long-term plasticity mechanisms (Aim 3a) and how silencing
the CA1 inputs to EC will affect contextual learning behavior (Aim 3b).
Despite 60 years of research on memory processing, we know surprisingly little about the organization
and function of hippocampal projection circuitry and the mechanisms by which memories modulate ongoing
sensory processing in the entorhinal cortex. Our study will combine state-of-the-art in vitro and in vivo
approaches, including electrophysiology, behavioral testing, and optogenetics, to provide a functional model of
the unexplored hippocampal-entorhinal cortex reciprocal circuit. Exciting pilot experiments from our lab have
already revealed a new pathway between the hippocampus and entorhinal cortex that implies a true reciprocal
feedback circuit loop. This circuit connects the hippocampus directly to entorhinal cortex output neurons that
project sensory information to the hippocampus. Our new circuit model is potentially transformative, for it
describes a route by which the hippocampus directly transmits memory input to the entorhinal cortex, with
minimal lag and transformation, to refine sensory output based on relevance and to quickly adapt behavior in
response to changing environmental demands. Such a function could be used by the brain to facilitate
reinforced learning, refine old memories, and form new memory associations. By identifying the neural circuit
interactions between the hippocampus and entorhinal cortex, our study will greatly improve our understanding
of the mechanisms that underlie the memory-related sensory processing deficits experienced by patients of
several neurological and neuropsychia...

## Key facts

- **NIH application ID:** 9936256
- **Project number:** 5R01NS109362-03
- **Recipient organization:** NEW YORK UNIVERSITY SCHOOL OF MEDICINE
- **Principal Investigator:** Jayeeta Basu
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $375,517
- **Award type:** 5
- **Project period:** 2018-09-01 → 2023-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9936256

## Citation

> US National Institutes of Health, RePORTER application 9936256, Synaptic and Circuit Interactions to Shape Multisensory Processing (5R01NS109362-03). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9936256. Licensed CC0.

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